The invention relates to a measurement method for lambda and/or the air/fuel ratio of combustion systems, especially internal combustion engines, by measuring and/or analyzing the individual components of the fuel, and the ambient air used for combustion of the fuel, and the exhaust gas, as well as to a device for implementation of such method.
A method of measuring various exhaust gas components, especially CO and HC, is described in Germain laid open No. 25 57 508.
On the basis of such measurements and measurement of the concentration of CO.sub.2, lambda and/or the air/fuel ratio may be determined. The disadvantage of this kind of measuring method is, however, that the sensors required are only suited for filtered exhaust gas, which will limit the dynamics of the measuring process, since rapid changes in the measured values cannot be reproduced precisely because of the filter, or, if very small filter units are used, because maintenance or replacement of the filter will be necessary after a very short time.